It is common knowledge that in addition to the slaughter of millions of innocent civilians, Nazism caused direct damage to patient care by euthanasia of the handicapped, gruesome human experimentation, and ethnic cleansing of German medical schools. In gastroenterology, 53 prominent academicians living in Nazi-occupied Europe were persecuted by the Nazis. Prior studies analyzed this persecution as it related to gastroenterologists rather than to patient care. What is not known, however, is that Nazi persecution led to a delay of more than one generation in the clinical application of major inventions by these gastroenterologists. These included flexible fiberoptic endoscopy, which was delayed from 1930 to 1957. Fiberoptic transmission was invented by Heinrich Lamm in 1930. Lamm was exiled from Nazi Germany in 1936, and this technique was clinically applied to endoscopy by Hirschowitz only in 1957. Another innovation was fecal occult blood testing for early colon cancer detection, which was devised by Ismar Boas before 1938. Boas committed suicide under Nazi oppression in 1938 and this modality was clinically applied by Greegor only in 1967. The acceptance of refugees from Nazi Germany or Austria into America or into the future State of Israel helped mitigate some of this damage. For example, eight eminent academic gastroenterologists who fled Nazi-occupied countries to then mandatory Palestine made major contributions to the development of academic gastroenterology in the soon-to-be established State of Israel.